The present invention relates to a technique of improving the file maintainability by storing files of an identical content in a distributed manner into a plurality of file servers.
Conventionally, a system is well known that backs up data into disk drives of redundant configuration. For example, JP1997-330182A discloses a technique of maintaining the data redundancy when a failure has occurred in a disk drive among a disk drive group of redundant configuration, which is realized by backing up data from another disk drive storing data identical to data stored in the failed disk drive to a backup disk drive.
A non-patent document “Maintenance-Free Global Data Storage,” INTERNET COMPUTING, U.S., IEEE COMPUTER SOCIETY, pp. 40–49, September-October, 2001 discloses a technique that relates to a file distribution/restore method referred to as M-of-N encoding in a system that stores files in a distributed manner into a plurality of file servers.